RU151127U1 - WASTE GAS PROCESSING DEVICE - Google Patents

Abstract

1. A device for treating exhaust gas containing acid mist emanating from an acid mist source, comprising a scrubber (1) disposed to receive exhaust gas that must be cleaned from acid mist, a scrubber (2) located downstream of the scrubber gas flow and designed to receive gas from the scrubber and to remove droplets from the gas, a fan (3), designed to create a gas flow and located in front of the scrubber (1) in the flow direction gas, as a result of which the gas scrubber (1) operates at a weak positive pressure, and a chimney (4) for discharging the cleaned dry gas into the ambient air, characterized in that the fan (3) is equipped with a device (5) for cleaning with sprayed water intended to clean the fan during use. 2. The device according to claim 1, characterized in that the source of acid mist formation is an apparatus for producing metal by electrolysis (PME). 3. The device according to claim 1, characterized in that the scrubber (1) is a wet scrubber that brings the gas to be cleaned into contact with the cleaning solution. The device according to any one of paragraphs. 1-3, characterized in that the mist eliminator (2) refers to the cyclone, laminar or mesh type, or any combination thereof. 5. The device according to any one of paragraphs. 1-3, characterized in that the fan (3) is a variable speed fan.

Description

FIELD OF TECHNOLOGY

This utility model relates to a device defined in the restrictive part of paragraph 1 of the utility model formula.

BACKGROUND OF USEFUL MODEL

In the reduction of a metal such as copper, copper is leached from a sulfide ore using sulfuric acid to form a copper sulfate solution, from which copper is obtained by precipitation by electrolysis. During electrolysis, a lead anode and a stainless steel cathode are immersed in an electrolytic bath containing copper sulfate / sulfuric acid solution. The electric current passing from the anode to the cathode causes an electrochemical reaction, which results in the deposition of metallic copper on the surface of the cathode. At the same time, oxygen is released on the surface of the anode, forming bubbles that separate from the anode and rise upward through the electrolyte. On the free surface of the electrolyte, the bubbles burst and form an acid fog, which is a dusty fog, consisting of a suspension of acid droplets in the air space above the electrolyte. Acid fog causes significant damage to the health of others. Accordingly, plants for the production of metal by electrolysis are equipped with a device for the treatment and disposal of acid mist. The electrolytic cells 7 are usually covered by casings 8 (see FIG. 1) used to collect acid mist and conduct it into the atmosphere through an acid mist treatment device.

FIG. 1 schematically illustrates a conventional prior art acid mist treatment device that comprises a scrubber 1 operating on a wet scrubbing principle and receiving an exhaust gas comprising acid mist sucked from a metal production plant using PME electrolysis. Scrubber 1 removes acid mist from the gas. Behind the scrubber 1, a mist eliminator 2 is located in the direction of the gas flow. From the mist eliminator 2, the gas is sucked in by the fan 3 and is led to the exhaust pipe 4, from which the purified gas leaves the surrounding air. The fan 3 creates a negative pressure, ensuring the suction of gas through the scrubber 1 and the mist eliminator 2. In addition, a throttle valve 6 is located behind the fan in the direction of gas flow in front of the pipe 4.

Such devices for treating acid mist are known, for example, from the international publication WO 2009/025837 A1 and the article “Copper production by electrolysis in the absence of acid mist: six years of industrial use” by Sabdiel Mella, Rodrigo Villarroel, Alejandro Lillo, SAME Ltda, Chile.

The problem is that the fan located behind the scrubber in the direction of the gas flow operates as a suction fan, so that it does not work optimally, and the gas flow can change very, very unexpectedly. Therefore, a throttle is required, which increases capital costs. In addition, the throttle increases energy costs for the fan drive motor. The fan also requires an efficient drive motor that increases capital costs. Another problem is that the scrubber operates under conditions of negative pressure, respectively, the negative pressure promotes evaporation and, thus, degrades the cleaning efficiency of the scrubber. In addition, the fan cannot be cleaned with water during use, as the flushing water will exit directly from the chimney. With the current fan cleaning system, it is necessary to stop the fan to clean it.

THE PROBLEM OF A USEFUL MODEL

The objective of this utility model is to eliminate the above disadvantages.

In particular, the objective of this utility model is to create an improved device, which from the point of view of capital and operating costs is more preferable in comparison with existing devices.

Another objective of this utility model is to provide a device in which a gas scrubber can operate at low positive pressure.

Another objective of this utility model is to create a device in which it is possible to clean the fan with water during its use without stopping the operation of the fan.

ESSENCE OF A USEFUL MODEL

The device in accordance with this utility model is characterized by the utility model described in paragraph 1.

According to this utility model, a fan is located in front of the scrubber in the direction of gas flow, as a result of which the scrubber operates at a low positive pressure.

In one embodiment of the device, the source of acid mist formation is the process of producing metal by electrolysis. Other process components can also create acid fog.

In one embodiment of the device, the fan is equipped with a spray water purifier for cleaning the fan during use.

In one embodiment of the apparatus, the scrubber is a wet scrubber that brings the gas to be cleaned into contact with the scrubbing solution.

In one embodiment of the device, the mist eliminator is of the cyclone, laminar or mesh type, or any combination thereof.

In one embodiment of the device, the fan is a variable speed fan.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following section, this utility model is described in detail using illustrative embodiments with reference to the accompanying drawings, in which

FIG. 1 schematically illustrates a known apparatus for treating acid mist and

FIG. 2 schematically illustrates one embodiment of a device in accordance with this utility model.

DETAILED DESCRIPTION OF A USEFUL MODEL

FIG. 2 illustrates an apparatus for treating exhaust gas containing acid mist generated during the production of metal by electrolysis of PME. The specified device contains a gas scrubber 1, designed to receive exhaust gas, which contains acid mist and which must be cleaned from it. In front of the gas scrubber 1, in the direction of the gas flow, there is a fan 3 designed to create a gas flow, so that the gas scrubber operates at a weak positive pressure. Placing the fan 3 in front of the gas scrubber promotes the latter to use less electricity, since there is no unnecessary throttle, and the same cleaning ability is achieved with a smaller fan motor. In one illustrative embodiment, capital costs are reduced by 10%, and operating costs - by 20% compared with the corresponding known technical solution. Since the scrubber operates at a weak positive pressure instead of the weak negative pressure used in the known technical solution shown in figure 1, the gas flow passing through the scrubber is reduced. In one embodiment, the difference between the gas flow amounts from 10.5% (at sea level) to 17% (3000 m above sea level), which means a 25% reduction in capital costs. Water purification of fan 3 is possible during its use. In one embodiment, such a solution means a 15% reduction in operating costs compared with the prior art. A system operating at positive pressure (even at low positive pressure) promotes condensation and thus improves cleaning ability. In accordance with FIG. 2 behind the scrubber in the direction of the gas flow there is a mist eliminator 2 into which the gas comes from the scrubber and which removes droplets from the gas. The specified device further comprises a chimney 4 for the removal of purified dry gas into the surrounding air space.

The fan 3 is equipped with a spray water cleaner 5 for cleaning the fan during use. The fan 3 may be a constant or variable speed fan.

The scrubber 1 is preferably a wet scrubber introducing the gas to be cleaned into contact with a scrubbing solution such as water.

The mist eliminator 2 may be a cyclone, laminar or mesh type, or any combination thereof.

This utility model is not limited to examples of the mentioned options for its implementation; on the contrary, it is possible to make many changes within the scope of legal protection of the essence of the utility model defined in the formula of the utility model.

Claims (5)

1. A device for treating exhaust gas containing acid mist emanating from an acid mist source, comprising a scrubber (1) disposed to receive exhaust gas that must be cleaned from acid mist, a scrubber (2) located downstream of the scrubber gas flow and designed to receive gas from the scrubber and to remove droplets from the gas, a fan (3), designed to create a gas flow and located in front of the scrubber (1) in the flow direction gas, as a result of which the gas scrubber (1) operates at a weak positive pressure, and a chimney (4) for discharging the purified dry gas into the ambient air, characterized in that the fan (3) is equipped with a device (5) for cleaning with sprayed water intended to clean the fan during its use. 2. The device according to p. 1, characterized in that the source of acid mist formation is a plant for producing metal by electrolysis (PME). 3. The device according to claim 1, characterized in that the scrubber (1) is a wet scrubber that brings the gas to be cleaned into contact with the cleaning solution. 4. The device according to any one of paragraphs. 1-3, characterized in that the mist eliminator (2) refers to the cyclone, laminar or mesh type, or any combination thereof. 5. The device according to any one of paragraphs. 1-3, characterized in that the fan (3) is a variable speed fan.

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